NMAT

Hi Vinnet Singh, NMAT registration starts from today.
You are asking about last year's NMAT score. Most of the business schools start classes for the session 2018-20. All the eligible candidates can apply directly to the NMAT website.

Sure, lots of non-maths graduate students prepare for cracking CAT. You need to practice maths question paper, tricks also matter to save time. Non-mathematics students need to practice and save time. Some questions are tricky and time taking.

If you are preparing for NMAT at some coaching centre like TIME, CL, IMS etc., they'll guide you on the topics to be covered and exam pattern. You may buy the guide if you are preparing on your own to be well versed with the content and pattern. According to trends of last 34 years, the cut-offs are usually around 210 marks out of 360. Scoring high above the cut-off significantly increases the final admit chances.

Minimum qualification required for MBA is graduation or equivalent degree. There are many institutes which provide MBA as well as PGDM courses, if you want to GET it from a top notch institute you need to have good scores in competitive exams too. As you are in 12th take your time, try to know more about competitive exams and institutes providing same courses. Fix your budget and then try to shortlist some colleges or take help of Shiksha. Com
At present IIM Ahmedabad and Bangalore are considered best for PGDM.

Self-study is sufficient. But, these coaching centers have mock test series, which are really helpful. Do appear for them. You need not be a classroom coaching student for this. Anyone can take these tests.

On a very realistic note, this is your last chance in CAT. I am saying this, because I did the same. Even I had 3.8 years of experience in IT with a mechanica degree. So, give it your best shot. If you are not able to clear CAT, then give GMAT, once you get 5 years work experience.

It's never too late. Start preparing for the exams from today itself. Do not keep it for June or July.
4-5 months of continuous preparation will get the task done.
Thanks and all the best.

10 popular MBA in Finance colleges in India are mentioned at the link provided below:
https://www.shiksha.com/mba/articles/know-the-top-10-mba-finance-colleges-in-india-blogId-7018
Please note: The list does not include IIMs or other B-Schools that offer PGP and MBA programmes where students can opt for specialisation in the second year.
The list includes programmes exclusively devoted to finance management.
Regards.

You can apply for MBA from FMS based on your CAT score. NMAT score is not accepted by FMS.